Akira innate immunity group has been studying the roles of Toll-like receptors and signaling, mainly by generating the knockout mice and analyzing them. Up to now, eleven members of the TLR family have been identified and deemed the total according to the human genome project. Each member recognizes a different component. 11 corresponding knockout mice families have also been created. It has been proven that acquired immunity was developed after and depends on innate immunity. Without activation of innate immunity, acquired immunity does not work even in higher organisms.